The Fatigue Failure Prediction of a Vari-Speed Drive with Different Rollers

Abstract

The track is the main failure part of vari-speed drive. The failure damage of the track disc will generate huge vibrations. The fatigue fracture became a problem during the normal working process of these machines. However, the steel roller has a higher deformation resistance capacity. The large contact stress of the steel roller will generate larger amplitude of cyclic stress and decrease the life of vari-speed drive. In order to improve the reliability of the vari-speed drive and increase the fatigue life, the rubber roller is used to replace the steel roller. A 3D model of the vari-speed drive is established by using Solidworks. The contact analysis of track is calculated by using Adams. The dynamic stress is analyzed by using the rain-flow counting method, which can determine the amplitudes and mean values of counted cycles. According to the assumption of a linear Palmgren–Miner hypothesis of damage accumulation and typical fatigue characteristics of the material, the fatigue failure life of the roller is calculated. The results show that the contact force of the steel roller is more than that of the rubber roller. The contact stress of the steel roller is much larger than the rubber roller. The fatigue life of the steel roller is less than that of the rubber roller. This paper presents a new method for solving the fatigue failure of the vari-speed drive.